Process of making double base powders



WILLIAM E. WAGNER, OF ALTON, ILLINOIS, ASSIGNOR TO WESTERN CARTRIDGECOMPANY, OF EAST ALTON, ILLINOIS, A CORPORATION OF 'DELAWABE PROCESS OFMAKING DOUBLE BASE EOWDERS N Drawing. Application filed April 7, 1930.Serial No. 442,471.

This, invention relates to propellant pow of nitro-cellulose are thenpurified of all acid ders and more particularly to those of the byrepeated boiling and washing. double base type, which may contain nitro-One of the objects of this invention, therecellulose withnitro-glycerin, ethylene glycol fore, is to provide a process of makingdouble dinitrate, diethylene glycol dinitrate, or any base powderswhereby the objectionable fea- 5e nitrate which is a solvent fornitro-cellulose, tures of the prior art processes are obviated, and willnot be decomposed by the acid used and more particularly whereby thelosses due in nitrating the nitro-cellulose. tothe employment of thefinely divided nitro- In the manufacture of nitro-cellulose-nitrmcellulose are avoided, more particularly in the glycerin powders asheretofore practiced, the separation of the same from the liquid. to

cellulose, after being nitrated in the usual Another object of this'invention is to obvi manner, is separated from the acid and puriate thenecessity, more particularly where fied to remove all traces of theacid. The straw cellulose is employed, of, first, making nitratedcellulose has then mixed therewith up the cellulose into sheets andcutting the nitroglycerin and the combination is treated sameintograins. as

to secure colloiding. In accordance with one Another object is to provide' a process of process, nitro-cellulose in the form of a finemaking double base powders whereby the pulp and made, for instance, bythe nitrapreliminary separation of the nitrated cellu tion of cottonlinters, is purified by repeated lose from the acid is obviated.

boiling and washing, first, with an alkali and When diethylene glycol isnitrated, it is 70 then with pure water; the nitro-cellulose beextremelydifiicult to separate the resulting ing in the form of a fine pulp in alarge quannitrate from the spent acid; for when strong tity of water, isthen mixed with nitro-glycmtratlng acids are used, the diethylene. gyerin by introducing the latter in the form C0l dinitrate forms in alayer 011 top of the of aspray, in order to form an emulsion in acid anddecomposes rapidly if allowed to. 3 the water; the mixture beingagitated so as to S and in Contact with the spent acid; on the cause thenitro-glycerin to combine with the ther hand, with weak nitrating acid,the finely divided nitro-cellulose. The particles filtrate bIm a nemulsion in the spent acid of nitro-cellulose and the nitro-gly'cerincomand can only be separated by reducing the i bined therewith arethenseparated from the t p atur as r instance, pouring the mix- B0 waterin a centrifugal machine dried and n i and Water. subjected to theaction of heated rolls,- in 0 Another object, therefore, of thisinvention order to secure the desired colloiding. While p g a means ofmore easily Separatthat process is practical, where the cellulose Suchfiltrates from the acid Used n their v 5 is in the form of cottonlinters, the fibres of "litralliofh which are sufiiciently large thatthey can be l l fi l ppe fm/m h separated from the nitrating acid bycen- Whlch s i trifuging without losing very much of the practlcalembodlment of thls t li 0 nitro ceuulose; when the cellulose is m to beunderstood, however, that this inventibn is susceptible'of variousembodiments from straw or similar material, the fibres are other thanthat described.

so reduced in size and character that the loss f P Q y separatlon, bycentnfug' embodiment of this invention, the double base 111g, 13lncleasflid to h a R Where 1t component such as nitro-glycerin orsimilar 45 effects economical conslderfltwnsa nitrate, or a suitableexplosive solvent or gea5 q been P TPQ Where Straw latinizer fornitro-cellillose is added to'the nil llose 15 used, s to m Q 6911111056p trated cellulose after its nitration and in the into paper and then toCut the Same into presence of the nitrating agent; the compieces ofsufficient size so they can be readily bined nitro-cellulose andnitro-glycerin are 5. separated from the nitrating acid; the grains thenseparated from the nitrating agent and.

Generally stated, in accordance witlf one purified and treated in anysuitable manner to secure grains in which nitro-cellulose is colloidedwith the nitro-glycerin. With nitrates such as diethylene glycoldinitrate,

however, which form emulsions with the ni-.

trating acid as heretofore noted, it is preferable to reverse theprocedure and nitrate the cellulose in the spent acid containing theemulsion of diethylene glycol dinitrate; for

in this way a means is provided for collecting trated with acid, such assulfuric and nitric acid, in the'usual manner. Before the separation ofthe nitrated cellulose and the acid, however, thenitro-glycerin isadded, preferably in the form of a spray. The mixture of nitro-celluloseand nitro-glycerin is agitated either mechanically or by air. Thiscauses the nitro-glycerin to combine with the nitro-cellulose particles,and these particles agglomerate to form a spongy mass, which.

. readily separates from the acid. This spongy mass can now be readilyseparated from the acid by either drawing off the latter or bycentrifuging. The agglomerated mass can now be purified by boiling andwashing, preferably with some alkali at the start, followed by purewater. The purified nitro-cellulosenitroglycerin can now be rolled intosheets or pressed into strings, with or without the application of heat,and cut into grains in the usual manner.

The cellulose which can be employed in this process may be any of thecellulose materials employed for that purpose. This invention is,however, particularly applicable to the employment of cellulose madefrom straw,

such as wheat straw, pulped and preliminarily purified in accordancewith any usual process well known to those skilled in the art. Thecellulose may be nitrated to any desired degree of nitration, inaccordance with the deowder, and the relative quantity of nitro-g ycerinor other explosive solvent or gelatinizer for nitrocellulose may be'suchas toproduce the desired combination. While nitro-glycerin isparticularly useful in this process, other suitable nitrates andexplosive solvents or gelatinizers for nitro-cellulose may be employed;it will, therefore be understood that the term ,nitrp-gl cerin as wellas the term nitrocellulose isused descriptively and functionally and notlimitati vely. It has been found that a double base propellant powdermade in-accordance with the process described is free from traces ofacid and stable; it will be Jmderstood,of course, thatsuitablestabilizing agents may be employed when desired or required.

It will be understood that certain features and sub-combinations are ofutility and may be employed without reference to other features andsub-combinations; that is contemplated by and is within-the scope of theappended claims. It is furthermore to be understood that various changesmay be made in details and operations Within the scope of the appendedclaims without departing from the spirit'of this invention; it is,therefore, to be understood that this invention is not to be limited tothe specific details and operations described.

Having thus described the invention, what isclaimed is:

- l. A process of making double base powders in which cellulose isnitrated, characterized by the feature that nitro-glycerin is addedimmediately after suchnitration.

2. A process of making double base powders in which cellulose isnitrated,-characterized by the feature that nitro-glycerin is added tothe nitrated cellulose in the presence of the nitrating agent.

3. A process of making double base powders in which cellulose isnitrated with acid, characterized by the feature that nitro-glycerin isadded to nitrated cellulose in the acid. as

4. A process of making double base powders in which finely dividedcellulose is subjected to a nitrating agent, characterized by thefeature that nitro-glycerin is mixed with the nitrated cellulose in thepresence of the 10( nitrating agent.

'5. A process of making double base powders *in which finely divided;cellulose is Hi": trated with acid, characterized by the feature thatnitro-glycerin is added to the nitrated 10E cellulose in the acid. Y

6. In the art of making double base powders, the process comprising,treating cellulose with a nitrating agent, adding nitroglycerintheretoand separating the nitrating 110 a ent.

7. In the art of making double base powders, the-process comprising,treating cellulose with nitrating acid, adding nitro-glycerinthereto,and separating the combined nitro- 11C cellulose and nitro-glycerinfromthe acid.

8. In the art of making double base powders, the process comprising,treating cellulose with nitrating acid, adding nitro-glycerinthereto,separating the combined nitro-cellu 120 lose and nitro-glycerin from theacid and" washing the combined intro-cellulose and nitro-glycerin.

9. In the art of making double base powders, the process comprising,treating finely divided cellulose with nitrating acid, mixingnitro-glycerin therewith and separating the colloided nitro-cellulosefrom the acid.

10. In the artof making double base owders, the process comprising,treating ely 1 divided cellulose with nitrating acid, mixingnitro-glycerin therewith, separating the colloided nitro-cellulose fromthe acid and washing the colloided nitro-cellulose.

11. In the art of making double base powders, the process comprising,treating cellulose with a nitrating agent, adding nitroglycerin thereto,agitating the mixture and separating the nitrating agent.

12. In the art of making double base powders, the process comprising,treating cellulose with nitrating acid, adding nitro-glycerin thereto,agitating the mixture and separating the combined nitro-cellulose andnitroglycerin from the acid.

In testimony whereof, I afiix my signature 7 I this 1st day of April,1930.

WILLIAM E. WAGNER.

